Biomedical subjects

I J Cook

Publications and source records attributed to I J Cook.

At least 37 records · Page 2Linked to original sources

PubMed1996

Spontaneous intramural haematoma of the oesophagus: radiologic recognition.

Spontaneous intramural haematoma of the oesophagus (SIHO) is an uncommon disorder. It presents usually with acute chest pain followed by dysphagia. This condition may mimic spontaneous rupture of the oesophagus (Boerhaave Syndrome), dissection of the thoracic aorta or acute myocardial infarction. Hence early accurate confirmation of the diagnosis by radiology is vital for the appropriate acute management. The condition is frequently mistaken for acute myocardial infarction which may prompt inappropriate thrombolytic therapy. The appearances on contrast studies of oesophagus and on CT scanning are characteristic. Despite this, the diagnosis may easily be missed, if appropriate careful radiological technique is not used. This paper reports three consecutive cases of SIHO managed in one institution. These cases illustrate that early gastrografin contrast radiology followed by barium contrast radiology and if necessary by thoracic CT is diagnostic in all cases of this condition.

Aged↗

PubMed1995

Esophageal achalasia and coexistent upper esophageal sphincter relaxation disorder presenting with airway obstruction.

Acute airway obstruction associated with esophageal achalasia is an uncommon but life-threatening complication. The pathophysiology of this phenomenon has not been fully defined. A fully documented case of coexistent esophageal achalasia and upper esophageal sphincter relaxation abnormality presenting with airway obstruction is reported. The patient was initially treated with Heller's myotomy but had a recurrence of respiratory distress. She was successfully treated by cricopharyngeal myotomy. The causes of gas entrapment and respiratory distress are likely to be due to failure of both swallow- and distention-induced upper esophageal sphincter relaxation. Cricopharyngeal myotomy is an effective treatment for this complication, probably by facilitating esophagopharyngeal gas venting.

Aged↗

PubMed1995

Influence of normal aging on oral-pharyngeal and upper esophageal sphincter function during swallowing.

The influence of aging on oral-pharyngeal swallowing was assessed by simultaneous manometry and videoradiography in 14 nondysphagic elderly individuals (mean age 76 yr) and 11 healthy, young controls (mean age 21 yr). Sphincter opening was diminished significantly in the elderly (P = 0.0001), but trans-sphincteric bolus flow rates were preserved. The increased impedance to trans-sphincteric bolus flow from reduced sphincter opening in the aged was reflected in a significant increase in hypopharyngeal intrabolus pressure (P = 0.003). Oral transit time was significantly prolonged in the aged (P = 0.01). The timing of upper esophageal sphincter (UES) manometric relaxation and of opening was significantly delayed in the aged (P = 0.0001), and this delay was comparable in magnitude to the prolongation in oral transit. Coordination of UES relaxation and opening with midpharyngeal contraction was not significantly affected by age. Deglutitive hyolaryngeal motion was not affected by age but was delayed by a duration equivalent to the prolongation in oral transit. We conclude that normal aging prolongs the oral-pharyngeal swallow that impairs UES opening but does not influence pharyngo-sphincteric coordination.

Adolescent↗

PubMed1994

Relationship between sleep patterns and human colonic motor patterns.

BACKGROUND/AIMS: The precise relationships among colonic motor patterns, depth of sleep, and awakening are incompletely understood. The aim of this study was to correlate human colonic motor patterns with sleep stage, nocturnal arousals, and waking. METHODS: We monitored sleep and correlated sleep stage, arousals, and waking with pressures (area under curve and propagating contractions) recorded from the entire colon in 11 healthy volunteers. RESULTS: Propagating contraction frequency (P = 0.01) and area under the curve (P = 0.001) were significantly reduced at night. There was a highly significant correlation between depth of sleep and suppression of area under curve (P = 0.001) and propagating contraction frequency (P = 0.0001). Propagating contractions were eliminated during slow-wave sleep. During rapid eye movement sleep, colonic pressure and propagating contraction frequency increased sharply to levels comparable with those found in stage 2 sleep. Transient arousal from stable sleep, with or without waking, was a potent and immediate stimulus for colonic propagating contractions. CONCLUSIONS: Sleep per se has a profound inhibitory effect on propagating and nonpropagating activity and is the major determinant of diurnal variation of colonic motility. Propagating contractions are eliminated in slow-wave sleep. Rapid eye movement sleep, arousals, and waking have immediate stimulatory effects on colonic motility.

Adolescent↗

PubMed1994

Influence of aging on oral-pharyngeal bolus transit and clearance during swallowing: scintigraphic study.

The aim of the study was to determine the influence of normal aging on regional transit and the efficiency of bolus clearance during the oral and pharyngeal phases of swallowing. We compared scintigraphically derived oral-pharyngeal transit times and isotope clearance during swallowing in 21 healthy aged volunteers (mean age 68 +/- 8 yr) and 9 young controls (mean age 28 +/- 7.5 yr). Subjects swallowed 5- and 10-ml water boluses mixed with 30 MBq 99mtechnetium tin colloid. Oral and pharyngeal transit times, pharyngeal clearance time, and postswallow residual counts in each region were derived from time-activity curves. Pharyngeal residual counts were significantly greater in the aged than in controls (P = 0.0008), but age did not influence oral residual. Aging significantly prolonged oral transit time (P = 0.02), pharyngeal transit time (P = 0.0004), and pharyngeal clearance time (P = 0.0001). We conclude that normal impairs the efficiency of pharyngeal clearance during swallowing, prolongs scintigraphic measures of oral-pharyngeal transit, and increases the exposure time of the glottis to the swallowed bolus.

Adult↗

PubMed1994

Influence of mucosal receptors on deglutitive regulation of pharyngeal and upper esophageal sphincter function.

The potential influence of mucosal sensory receptors on the regulation of oral-pharyngeal swallow events was studied in 15 healthy volunteers using simultaneous videoradiography and manometry. We determined the effects of selective pharyngeal and oral plus pharyngeal anesthesia on the following temporal and manometric measures in response to liquid and viscous swallows: regional transit and clearance times; motion of hyoid and larynx; upper esophageal sphincter relaxation, opening, and closure; and pharyngeal contraction wave characteristics. Under the influence of mucosal anesthesia no subjects demonstrated aspiration during deglutition. Neither regional transit and clearance times nor pharyngosphincteric coordination was influenced significantly by pharyngeal mucosal anesthesia or oral plus pharyngeal anesthesia. Although midpharyngeal and distal pharyngeal contraction amplitudes were not influenced by mucosal anesthesia, midpharyngeal contraction wave duration was reduced significantly by both pharyngeal (P = 0.02) and oral plus pharyngeal anesthesia (P = 0.0005). We conclude that 1) neither elicitation of the pharyngeal swallow response nor temporal regulation among swallow events is dependent on mucosal sensory receptors and 2) duration of the pharyngeal contraction is influenced by sensory input from the oral-pharyngeal mucosa.

Adolescent↗

PubMed1993

Cricopharyngeal function and dysfunction.

The cricopharyngeus is a narrow band of muscle strategically placed between the pharynx and esophagus. Its normal function is vital to the efficient transfer of foodstuffs to the esophagus. Cine- and videoradiography are the major methods of studying the pharyngo-esophageal segment. More recently, refinements in manometric methods have complemented radiology, and have enabled us to achieve a better understanding of cricopharyngeal function in health and disease. Such an understanding of the physical forces necessary for normal bolus transfer, and the recognition of abnormal patterns of pharyngeal and cricopharyngeal motility, will hopefully lead us to a more rational approach to therapy in patients with pharyngeal dysphagia.

Deglutition↗

PubMed1992

Pharyngeal (Zenker's) diverticulum is a disorder of upper esophageal sphincter opening.

Pharyngeal coordination, sphincter opening, and flow pressures during swallowing were investigated in patients with pharyngeal (Zenker's) diverticula. Fourteen patients with diverticula and 9 healthy age-matched controls were studied using simultaneous videoradiography and manometry. Pharyngeal and upper esophageal sphincter pressures were recorded by a perfused side hole/sleeve assembly. Temporal relationships among swallowing events, extent of sphincter opening during swallowing, and intrabolus pressure during bolus passage across the sphincter were measured. The timing among pharyngeal contraction and sphincter relaxation, opening, and closure did not differ between patients and controls. Sphincter opening was significantly reduced in patients compared with controls in sagittal (P = 0.0003) and transverse (P = 0.005) planes. Manometric sphincter relaxation was normal in patients. Intrabolus pressure was significantly greater in patients than in controls (P = 0.001). It is concluded that Zenker's diverticulum is a disorder of diminished upper esophageal sphincter opening that is not caused by pharyngosphincteric incoordination or failed sphincter relaxation. Incomplete sphincter opening is likely to cause dysphagia. Increased hypopharyngeal pressures during swallowing are probably important in the pathogenesis of the diverticulum.

Aged↗

PubMed1991

Normal and disordered swallowing: new insights.

Swallowing is a complex sequence of integrated motor events which is programmed entirely within a 'pattern generator', the medullary swallow centre. The swallow is not a reflex but rather a programmed response which is only initiated given the right combination of cortical and peripheral sensory cues to the medulla. Interruption of these afferent pathways profoundly influences the ability to initiate a swallow. While the basic sequence of motor events that constitutes a swallow is constant, the temporal relationships among component events are modifiable according to the characteristics of the swallowed bolus. The pathophysiology of dysphagia can be categorized on the basis of dysfunction of one or more of seven broad mechanisms that make up the swallow: bolus preparation, lubrication, oral delivery, palatal closure, airway closure, pharyngeal propulsion and UOS opening. This mechanistic approach originates directly from the videoradiographic observations and provides a rational basis for treatment. Videoradiography is the single most valuable technique in the evaluation of oral pharyngeal dysphagia. Oesophagoscopy and laryngoscopy should be performed in most cases because small tumours in the region can mimic pharyngeal motor disorders and may be easily overlooked. Manometry is providing valuable physiological and pathophysiological information about swallowing but, as an adjunct to videoradiography, only provides additional important information in the minority of patients undergoing investigation.

Deglutition↗

PubMed1991

Videoradiographic, manometric, and electromyographic analysis of canine upper esophageal sphincter.

We assessed upper esophageal sphincter (UES) function in dogs by concurrent recording of cricopharyngeal electromyographic (EMG) activity, intraluminal pressure, and dimensional changes of the pharyngoesophageal junction at rest and during swallowing. Radial and axial pressure profiles of the UES were determined by continuous pull-through manometry. EMG activity of the cricopharyngeus and thyropharyngeus muscles were correlated with UES pressure under static conditions. We also quantified the temporal relationships among EMG activity of the cricopharyngeus, UES pressure, and pharyngoesophageal junction dimensional changes during swallowing of 2, 4, and 6 ml of barium. When the dogs were prone, the anterior and posterior UES pressures were about twice the lateral pressures and the axial length of the UES was approximately 4 cm. All radial pressures equalized to approximately 20 mmHg when the dogs lay on their sides. The peak pressure zone of the UES corresponded closely with the level of the cricopharyngeal electrode, and resting UES pressure correlated closely with cricopharyngeal but not thyropharyngeal EMG activity. During swallowing, the cricopharyngeus relaxed approximately 200 ms before UES opening and 100 ms before UES relaxation. Superior movement of the hyoid and the larynx was associated temporally with UES relaxation, while anterior movement was associated with UES opening. Increases in bolus volume significantly increased maximal sagittal UES diameter during UES opening but did not alter temporal changes in UES function.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Manometric characteristics of glossopalatal sphincter.

When a liquid bolus is held in the mouth, the posterior tongue and soft palate pinch together to prevent premature spillage of the bolus into the oropharynx. We propose that this glossopalatal closure acts as a glossopalatal sphincter (GPS). In this investigation, we studied glossopalatal closure by obtaining concurrent manometric and radiographic recordings of barium swallows in healthy volunteers. Manometry was done by both a continuous pull through method and also by a stationary catheter technique using a ribbon catheter with multiple sideholes spaced at 1-cm intervals. The results showed that when the mouth was loaded with a fluid bolus, the closed glossopalatal segment generated an asymmetric high-pressure zone with greater pressures toward the tongue and palate than laterally. With swallowing, the glossopalatal sphincter high-pressure zone relaxed and the glossopalatal sphincter opened to allow barium to flow from the mouth into the oropharynx. We conclude that the glossopalatal sphincter functions as a physiological sphincter in that it (1) generates a sustained high-pressure zone and closure when a liquid bolus is held in the mouth and (2) relaxes and opens with swallowing.

Adolescent↗

PubMed1990

Biomechanics of cricopharyngeal bars.

Patients with a prominent cricopharyngeal bar visible on radiography are generally considered to have spasm of the cricopharyngeus, which is the major muscle component of the upper esophageal sphincter. This condition has been termed "cricopharyngeal achalasia." The aim of this study was to determine the pathogenesis of cricopharyngeal bars. Concurrent videofluoroscopic and manometric examinations of the pharynx and upper esophageal sphincter were performed in a cohort of six patients with prominent cricopharyngeal bars and in eight control volunteers. In each subject, swallows of 2-30-mL barium boluses were recorded. The patients with cricopharyngeal bars showed (a) normal peristaltic contraction in the pharynx, (b) normal axial upper esophageal sphincter pressure and relaxation, (c) normal flow rate across the upper esophageal sphincter, and (d) normal duration of upper esophageal sphincter opening for different bolus volumes. The major abnormalities in the patients with cricopharyngeal bars were (a) reduced maximal dimensions of the upper esophageal sphincter during the transsphincteric flow of barium and (b) increased intrabolus pressure upstream to the upper esophageal sphincter. Thus, the increase in intrabolus pressure preserved normal transsphincteric flow rates even though the upper esophageal sphincter did not open normally. Overall, the constellation of findings in the patients studied suggests that the underlying pathogenesis of their cricopharyngeal bar was reduced muscle compliance wherein the relaxed cricopharyngeus did not distend normally during swallowing.

Adult↗

PubMed1990

Effect of dietary fiber on symptoms and rectosigmoid motility in patients with irritable bowel syndrome. A controlled, crossover study.

The aims of this study were to determine (a) whether dietary fiber supplements modify symptoms in patients with irritable bowel syndrome, (b) the effect of fiber on rectosigmoid pressures, and (c) the relationship, if any, between rectosigmoid pressure and symptoms. Fourteen patients entered and 9 completed a double-blind, controlled, cross-over study of 7 mo duration. The mean age was 26 yr (range, 18-37). Patients received 4 cookies daily containing 20 mg corn fiber or placebo. Symptoms and compliance were evaluated monthly. Rectosigmoid pressures and dietary intake were evaluated at the outset and completion of each study arm. Symptoms improved during both fiber and placebo treatments. Those symptoms demonstrating significant improvement with time were pain severity, stool frequency, stool consistency (p = 0.001), number of additional gastrointestinal symptoms present (p = 0.02), and total symptom score (p less than 0.001). Rectosigmoid pressures were not significantly altered by fiber or placebo. Fasting pressures at the distal recording site tended to correlate with pain severity (r = 0.6; p = 0.06). It was concluded that (a) corn fiber and placebo were both effective in alleviating symptoms, (b) there was a correlation between symptom severity and fasting rectosigmoid pressure, and (c) there was a trend toward reduction in fasting and postprandial rectosigmoid pressures after fiber therapy.

Adult↗

PubMed1990

Effect of swallowed bolus variables on oral and pharyngeal phases of swallowing.

In this investigation, we studied the effects of bolus volume and viscosity on the quantitative features of the oral and pharyngeal phases of swallowing. Concurrent videofluoroscopic and manometric studies were done in 10 healthy volunteers who were imaged in lateral projection. Videofluorography was done at 30 frames/s while concurrent manometry was done with 5 intraluminal transducers that straddled the pharynx and upper esophageal sphincter (UES). Submental electromyography was recorded also. Swallows of 2-20 ml were recorded for low-viscosity liquid barium and high-viscosity paste barium. Analysis indicated that the major effect of increases in bolus volume was an earlier onset of anterior tongue base movement, superior palatal movement, anterior laryngeal movement, and UES opening. These events provide receptive adaptation for receiving a swallowed bolus. Earlier UES opening was associated with an increase in the duration of sphincter opening and sphincter diameter. The major effects of high bolus viscosity, unrelated to bolus volume, were to delay oral and pharyngeal bolus transit, increase the duration of pharyngeal peristaltic waves, and prolong and increase UES opening. Thus the specific effect of bolus viscosity per se differs substantially from that of bolus volume. We conclude that 1) specific variables of swallowing are affected significantly by the variables of the swallowed bolus, such as volume and viscosity; 2) overall, bolus volume and viscosity affect swallowing in a different manner; and 3) the study findings have implications about the neural control mechanisms that govern swallowing as well as about the diagnosis and treatment of patients with abnormal oral-pharyngeal swallowing.

Adult↗

PubMed1990

[Pathogenesis and treatment of Zencker's diverticulum].

The aims of this study were: 1) To measure pharyngeal and upper oesophageal function manometrically at the same time as recording video images of the patient swallowing barium, in normal controls and patients with Zenker's diverticulum, and, 2) In those patients who progressed to surgery to biopsy the cricopharyngeus and compare the findings with biopsies from normal controls. Subjects were seated in front of a fluoroscope and video images of a barium swallow were synchronised with a multichannel recording catheter which contained 3 perfused side holes 1 cm apart (situated in the pharynx) and a 4 cm long perfused sleeve pressure sensor (positioned across the upper oesophageal sphincter). The coordination of the upper sphincter with swallowing, its relaxation, the pressures generated in the distal pharynx and the maximum luminal area of the open upper sphincter, were calculated for different volumes of barium swallowed in 11 patients with a Zenker's diverticulum (mean age 71 years, range 50-99) and 9 normal controls (mean age 65 years, range 55-86). Seven patients progressed to cricopharyngeal myotomy and their biopsies were compared with biopsies from 9 normal controls. In patients with Zenker's diverticulum intrapharyngeal pressures during barium swallows were significantly greater (p less than .05) and maximal luminal areas of the open sphincter were significantly less (p less than .05) than in control patients. In patients having a cricopharyngeal myotomy, intrapharyngeal pressures and maximum luminal areas returned to normal after surgery. The cricopharyngeus muscle of patients with a Zenker's diverticulum showed significantly increased fibrosis compared with normal controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

Upper esophageal sphincter tone and reactivity to stress in patients with a history of globus sensation.

Anxiety and abnormal upper esophageal sphincter function have been ascribed ill-defined roles in the etiology of globus sensation. In this study, we examined the psychological profile and effect of acute mental stress (dichotic listening task) on UES tone in seven patients reporting to the clinic with globus sensation and 13 healthy controls. Alterations in heart rate, blood pressure, frontalis EMG, and skin conductance confirmed the effectiveness of the stress test in patients and controls. During resting conditions, UES pressure (mean +/- SE) in patients (40.4 +/- 4.6 mm Hg) did not differ significantly from controls (46.5 +/- 4.7 mm Hg). In response to stress, UES pressure rose by 31% in patients (P = 0.04) and by 25% in controls (P = 0.002). The stress-induced rise in UES pressure in patients (9.5 +/- 3.8 mm Hg) was not significantly different to that observed in controls (11.8 +/- 3.0 mm Hg). Psychological profiles of globus patients presenting to the clinic revealed them to be more introverted, anxious, neurotic, and depressed than normal controls. We conclude that in patients with a history of globus sensation, resting UES pressure and its response to stress is normal. Although individuals presenting to the clinic with globus sensation showed increased levels of psychoneurosis, acute, predictable stress is not a factor in the genesis of globus sensation. UES hyperresponsiveness to other stimuli or subjective intolerance to changes in UES pressure could account for symptoms of globus sensation.

Adult↗

PubMed1989

Timing of videofluoroscopic, manometric events, and bolus transit during the oral and pharyngeal phases of swallowing.

The aims of this study were to evaluate and quantify the timing of events associated with the oral and pharyngeal phases of liquid swallows. For this purpose, we recorded 0-20 ml barium swallows in three groups of volunteers using videoradiographic, electromyographic, and manometric methods. The study findings indicated that a leading complex of tongue tip and tongue base movement as well as onset of superior hyoid movement and mylohyoid myoelectric activity occurred in a tight temporal relationship at the inception of swallowing. Two distinct general types of normal swallows were observed. The common "incisor-type" swallow began with the bolus positioned on the tongue with the tongue tip pressed against the upper incisors and maxillary alveolar ridge. At the onset of the "dipper-type" swallow the bolus was located beneath the anterior tongue and the tongue tip scooped the bolus to a supralingual location. Beginning with tongue-tip peristaltic movement at the upper incisors, the two swallow types were identical. Swallow events that occurred after lingual peristaltic movement at the maxillary incisors showed a volume-dependent forward migration in time that led to earlier movement of the hyoid and larynx as well as earlier opening of the upper esophageal sphincter in order to receive the large boluses that arrived sooner in the pharynx during the swallow sequence than did smaller boluses. The study findings indicated that timing of swallow events should be considered in reference to both swallow type and bolus volume. The findings also indicated an important distinction between peristaltic transit and bolus clearance.

Adolescent↗

PubMed1989

Opening mechanisms of the human upper esophageal sphincter.

Our goals in this study were to evaluate the mechanisms operative in swallow-associated opening of the upper esophageal sphincter (UES) and to determine the dynamics of fluid flow across the sphincter. For this purpose, we obtained concurrent videofluorographic and manometric studies of 2- to 30-ml barium swallows in 15 normal subjects. We found that the resting UES high-pressure zone corresponded closely with the location of the cricopharyngeus. The findings indicated that manometric UES relaxation and anterior hyoid traction on the larynx invariably preceded UES opening. With graded increases in bolus volume, progressive increases occurred in UES diameter, cross-sectional area, flow duration, and transsphincteric flow rate. Intrabolus pressure upstream to the UES and within the UES at its opening during transsphincteric flow of barium remained within a narrow physiological range of less than 10 mmHg up to a bolus volume of 10 ml. With increases in bolus volume, anterior hyoid movement, UES relaxation, and UES opening occurred sooner in the swallow sequence to accommodate the early entry of large boluses into the pharynx. We conclude that during swallowing 1) normal UES opening involves sphincter relaxation, anterior laryngeal traction, and intrabolus pressure, 2) volume-dependent adaptive changes in UES dimension accommodate large bolus volumes and flow rates with minimal requirement for increases in upstream, or intrasphincteric, intrabolus pressure or UES opening duration, and 3) volume-dependent changes in UES dimensions as well as timing of UES relaxation and opening indicate a sensory feedback mechanism that modulates some components of the swallow response generated by the brain stem swallow centers.

Adult↗